在此Github问题中，我发现 pip 10不再卸载distutils软件包.因此我将等级降为8.1.1.现在就可以了.

I found in this Github issue that pip 10 no longer uninstalls distutils packages. So I downgraded to pip 8.1.1. And now it works.

如果正在查看此问题的任何人都知道如何使用pip 10.0.0卸载或升级 distutils 软件包，请在此告诉我. :)

If anybody, who are viewing this question, knows how to uninstall or upgrade distutils package with pip 10.0.0, please let me know here. :)

(如果有人需要)
为了降低点数，我使用了以下内容:

(If anybody needs)
And to downgrade pip, I used the following:

sudo -H pip3 install pip==8.1.1

sudo -H pip3 install pip==8.1.1